1. Field of the Invention
The present invention relates to a printing apparatus, a control method for controlling the printing apparatus, and a storage medium.
2. Description of the Related Art
Some printing apparatuses are configured to convey a sheet from any one of a plurality of sheet storage units and print an image on the conveyed sheet. Japanese Patent Application Laid-Open No. 2007-76868 discusses a technique for grouping a plurality of sheet storage units as a single sheet storage unit. Sheet storage units containing sheets of the same type and the same size are grouped together, and an automatic cassette change (ACC) control is performed within the grouped sheet storage units. Such a technique virtually enables printing using a large-capacity sheet storage unit.
The foregoing conventional technique has the following problem. Suppose, for example, that a user uses a print on demand (POD) machine to group sheet storage units on a paper feed deck and performs printing using the grouped sheet storage units. If another user with the intention of performing different printing presses an open button on a sheet storage unit that is currently feeding sheets, an electronic lock on the sheet storage unit will neither be released nor be opened.
If another user presses an open button on another sheet storage unit in the group, however, the sheet storage unit will be electronically unlocked and opened. If the sheet storage unit currently feeding sheets runs out of paper when another sheet storage unit in the group to which the sheet storage unit currently feeding sheets belongs is open, the sheet feeding source is not able to be switched to the sheet storage unit that is open. If there is no other sheet storage cassette that is capable of feeding sheets, the existing print job stops printing due to paper-out.